JP6992562B2 - Control device for vehicle power transmission device - Google Patents

Description

The present invention relates to a control device for a vehicle power transmission device having a plurality of power transmission paths provided in parallel between a power source and a drive wheel.

A first power transmission path via a gear mechanism having a gear stage, which is provided in parallel between an input rotating member through which the power of the power source is transmitted and an output rotating member that outputs the power to the drive wheels, and nothing. A control device for a power transmission device for a vehicle having a plurality of power transmission paths with a second power transmission path via a step speed change mechanism is well known. For example, it is the control device of the power transmission device described in Patent Document 1. In this Patent Document 1, the primary pulley and the secondary pulley formed by the engagement of the first power transmission path via the gear mechanism formed by the engagement of the first engagement device and the engagement of the second engagement device are described. In a power transmission device provided in parallel with a second power transmission path via a stepless speed change mechanism around which a transmission element is wound, a second is based on an instruction pressure in hydraulic control for the second engagement device. When it is determined whether the engaging device is in the fully released state or the slipped state, and when it is determined that the second engaging device is in the fully released state or the slipped state, the secondary pulley is over-rotated. It is disclosed that the gear ratio of the stepless speed change mechanism is controlled with the highest priority given to suppressing the pressure.

The gear ratio is "rotational speed of the rotating member on the input side / rotational speed of the rotating member on the output side". For example, the gear ratio of the continuously variable transmission mechanism is "rotational speed of primary pulley / rotational speed of secondary pulley". The gear ratio of the vehicle power transmission device is "rotational speed of the input rotating member / rotational speed of the output rotating member". The high side in the gear ratio is the high vehicle speed side on which the gear ratio becomes smaller. The low side in the gear ratio is the low vehicle speed side on which the gear ratio becomes large. For example, the lowest gear ratio is the gear ratio on the lowest vehicle speed side, which is the lowest vehicle speed side, and is the maximum gear ratio at which the gear ratio is the largest value.

Japanese Unexamined Patent Publication No. 2017-37683

By the way, the operating state of the second engaging device is represented by, for example, four states of complete release, complete engagement, release transient, and engagement transient. When the continuously variable transmission mechanism is controlled according to the operating state of the second engaging device, if the operating state of the second engaging device cannot be appropriately determined, for example, in a belt-type continuously variable transmission, a transmission element is used. There is a risk of slipping or making it difficult to achieve the target gear ratio. When the operating state of the second engaging device is switched, or when the operating state of the second engaging device is in a transient state, or when the electromagnetic valve that regulates the hydraulic pressure supplied to the second engaging device fails. In such cases, the state of hydraulic pressure control for the second engaging device and the actual operating state of the second engaging device are likely to differ. Therefore, in the determination of the operating state of the second engaging device based only on the instruction pressure in the hydraulic control for the second engaging device, the determination accuracy may deteriorate. It is desired to accurately determine the four states of the second engaging device.

The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a control device for a vehicle power transmission device capable of improving the determination accuracy of the operating state of the second engaging device. To provide.

The gist of the first invention is (a) the power provided in parallel between an input rotating member to which the power of the power source is transmitted and an output rotating member to output the power to the drive wheels. Each of the input rotating members is provided with a plurality of power transmission paths capable of transmitting power to the output rotating member, and the plurality of power transmission paths have a gear stage formed by the engagement of the first engaging device. A vehicle power transmission device having a first power transmission path via a gear mechanism and a second power transmission path via a stepless speed change mechanism formed by engagement of a second engagement device. It is a control device, and (b) is completely released, completely engaged, released transient, and engaged based on the state of hydraulic control for the second engaging device and the state of the differential rotation speed in the second engaging device. It is determined whether or not the transition condition for determining the switching of the operating state of the second engaging device represented by the four states of the combined transient is satisfied, and based on the determination result of whether or not the transition condition is satisfied. The operation state determination unit for determining which of the four states the operating state of the second engaging device has been switched to is included.

The second invention is the control device for the vehicle power transmission device according to the first invention, wherein the continuously variable transmission mechanism is a transmission wound between a primary pulley, a secondary pulley, and each pulley. A belt-type continuously variable transmission having an element, which is applied by a target value of thrust of the primary pulley for pinching the transmission element applied by the hydraulic actuator of the primary pulley, and a hydraulic actuator of the secondary pulley. Shift control that calculates the input torque to the continuously variable transmission mechanism used for calculating the target value of the thrust of the secondary pulley that clamps the transmission element according to the determined operating state of the second engaging device. To include more parts.

Further, in the third invention, in the control device of the vehicle power transmission device according to the second invention, the input torque to the stepless speed change mechanism realizes the target gear ratio of the stepless speed change mechanism. The primary pulley and the secondary, which are necessary for the first input torque used for calculating the thrust ratio, which is the value of the ratio of the thrust of the primary pulley to the thrust of the secondary pulley, and for preventing the transmission element from slipping. This is the second input torque used to calculate each thrust in the pulley.

Further, the fourth invention is the control device of the vehicle power transmission device according to any one of the first to third inventions, wherein the operating state determination unit is the second engaging device. When the transition condition that the hydraulic control for engaging the second engaging device is activated is satisfied in the completely released state or the releasing transient state, the second engaging device engages. It is to determine that the state has been switched to the transient state.

Further, the fifth invention is the control device of the vehicle power transmission device according to any one of the first to the fourth inventions, wherein the operation state determination unit is the second engagement device. In the fully engaged state, the disengagement transient state, or the engagement transient state, the second engagement device is released in the region where the input rotation speed of the stepless speed change mechanism is equal to or higher than the predetermined rotation speed. The hydraulic control is operating, the instruction pressure in the hydraulic control for the second engaging device is equal to or less than the first predetermined instruction pressure, and the difference rotation speed in the second engagement device is the first predetermined difference rotation. In the transition condition that the speed is larger than the speed, and in the region where the input rotation speed of the stepless speed change mechanism is less than the predetermined rotation speed, the hydraulic control for releasing the second engaging device is operating, and the first 2 The transition condition that the indicated pressure in the hydraulic control for the engaging device is equal to or less than the second predetermined instruction pressure lower than the first predetermined instruction pressure, and both the first engagement device and the second engagement device are released. When any of the transition conditions that the neutral state of the vehicle power transmission device is determined is satisfied, it is determined that the second engaging device has been switched to the completely released state. To do.

Further, the sixth invention is the control device of the power transmission device for a vehicle according to any one of the first to fifth inventions, wherein the operating state determination unit is the second engaging device. In the state of complete release, the state of release transient, or the state of engagement transient, the hydraulic control for engaging the second engaging device is activated, and the hydraulic control for the second engaging device is performed. The transition condition that the indicated pressure is equal to or higher than the third predetermined indicated pressure and the difference rotation speed in the second engaging device is smaller than the second predetermined difference rotation speed, and the hydraulic control for the second engaging device are as follows. When any of the transition conditions of the transition from the hydraulic control for engaging the second engaging device to the hydraulic control for maintaining the second engaging device in a fully engaged state is satisfied. The purpose is to determine that the second engaging device has been switched to the fully engaged state.

Further, the seventh invention is the control device of the power transmission device for a vehicle according to any one of the first to sixth inventions, wherein the operating state determination unit is the second engaging device. It is said that the hydraulic control for releasing the second engaging device is operating in the fully engaged state, and the difference rotation speed in the second engagement device is equal to or higher than the third predetermined difference rotation speed. When the transition condition is satisfied, it is determined that the second engaging device has been switched to the release transient state.

Further, the eighth invention is the control device of the vehicle power transmission device according to any one of the first to seventh inventions, wherein the operating state determination unit is the second engaging device. When the transition condition that the hydraulic control for releasing the second engaging device is activated is satisfied in the engagement transient state, the second engaging device is switched to the release transient state. It is to judge that it was.

Further, the ninth invention is the control device for the vehicle power transmission device according to any one of the first to eighth inventions, wherein the hydraulic control for the second engaging device is the second. The hydraulic control for engaging the engaging device or the hydraulic control for releasing the second engaging device, and the hydraulic control for engaging the second engaging device, the first power transmission path is formed. The hydraulic control for engaging the second engaging device in the control for switching from the state to the state in which the second power transmission path is formed, or both the first engaging device and the second engaging device are released. It is a hydraulic control that engages the second engaging device in the control of switching from the neutral state of the vehicle power transmission device to the state in which the second power transmission path is formed, and releases the second engaging device. The hydraulic control is a hydraulic control that releases the second engaging device in a control for switching from a state in which the second power transmission path is formed to a state in which the first power transmission path is formed, or the second power transmission. It is a hydraulic control that releases the second engaging device in the control of switching from the state where the path is formed to the neutral state of the vehicle power transmission device.

According to the first invention, the complete release, the complete engagement, the release transient, and the engagement transient are based on the state of the hydraulic control for the second engaging device and the state of the differential rotation speed in the second engaging device. It is determined whether or not the transition condition for determining the switching of the operating state of the second engaging device represented by the four states is satisfied, and the second is based on the determination result of whether or not the transition condition is satisfied. Since it is determined which of the four states the operating state of the engaging device has been switched to, the tendency of whether the hydraulic pressure of the second engaging device is raised or lowered, and / or , The four states of the second engaging device are appropriate, taking into account the actual state of how the second engaging device is actually operating, in addition to the state of the indicated pressure in the hydraulic control for the second engaging device. Can be determined. Therefore, it is possible to improve the accuracy of determining the operating state of the second engaging device.

Further, according to the second invention, the input torque to the continuously variable transmission mechanism used for calculating the target value of the thrust of the primary pulley and the target value of the thrust of the secondary pulley is determined by the second engaging device. Since it is calculated according to the operating state, the continuously variable transmission mechanism can be appropriately controlled by using the input torque that matches the operating state of the second engaging device that has been accurately determined.

Further, according to the third invention, the input torque to the continuously variable transmission mechanism is the first input torque used for calculating the thrust ratio that realizes the target gear ratio of the continuously variable transmission mechanism, and the slip of the transmission element. Since it is the second input torque used for calculating the thrust required for prevention, the continuously variable transmission mechanism can be appropriately controlled.

Further, according to the fourth invention, the transition condition that the hydraulic control for engaging the second engaging device is activated when the second engaging device is in the completely released state or the releasing transient state. When is satisfied, it is determined that the second engaging device has been switched to the engagement transient state, so that the engagement transient state of the second engagement device can be appropriately determined.

Further, according to the fifth invention, when the second engaging device is in a fully engaged state, a release transient state, or an engagement transient state, the input rotation speed of the stepless speed change mechanism is a predetermined rotation speed. In the above-mentioned region, the hydraulic control for releasing the second engaging device is operating, the instruction pressure in the hydraulic control for the second engagement device is equal to or less than the first predetermined instruction pressure, and the second. When the transition condition that the differential rotation speed in the engaging device is larger than the first predetermined difference rotation speed is satisfied, it is determined that the second engaging device has been switched to the completely released state, so that the input rotation When the speed is equal to or higher than the predetermined rotation speed, the state of complete release of the second engaging device can be appropriately determined. Further, in the region where the input rotation speed of the stepless speed change mechanism is less than the predetermined rotation speed when the second engagement device is in the fully engaged state, the release transient state, or the engagement transient state, the second engagement device is used. The transition condition that the hydraulic pressure control for releasing the engaging device is operating and the instruction pressure in the hydraulic control for the second engagement device is equal to or less than the second predetermined instruction pressure lower than the first predetermined instruction pressure is satisfied. If this is the case, it is determined that the second engaging device has been switched to the fully released state. Therefore, when the input rotation speed is less than the predetermined rotation speed, the completely released state of the second engaging device is appropriately set. It can be determined. Further, when the second engaging device is in the fully engaged state, the release transient state, or the engaging transient state, the transition condition that the neutral state of the power transmission device for the vehicle is determined is established. In this case, since it is determined that the second engaging device has been switched to the completely released state, the completely released state of the second engaging device can be appropriately determined.

Further, according to the sixth invention, when the second engaging device is in the completely released state, the releasing transient state, or the engaging transient state, the hydraulic control for engaging the second engaging device is activated. The transition that the instruction pressure in the hydraulic control for the second engaging device is equal to or higher than the third predetermined instruction pressure, and the difference rotation speed in the second engagement device is smaller than the second predetermined difference rotation speed. When the condition is satisfied, it is determined that the second engaging device has been switched to the fully engaged state, so that the fully engaged state of the second engaging device can be appropriately determined. Further, when the second engaging device is in a completely released state, a release transient state, or an engaging transient state, the hydraulic control for the second engaging device is changed from the hydraulic control for engaging the second engaging device. 2 When the transition condition that the engagement device is shifted to the hydraulic control for maintaining the fully engaged state is satisfied, it is determined that the second engaging device has been switched to the fully engaged state. Therefore, the state of complete engagement of the second engaging device can be appropriately determined.

Further, according to the seventh invention, when the second engaging device is in a fully engaged state, the hydraulic control for releasing the second engaging device is operating, and the second engaging device is activated. When the transition condition that the difference rotation speed is equal to or higher than the third predetermined difference rotation speed is satisfied, it is determined that the second engagement device has been switched to the release transient state. The state of the release transition can be appropriately determined.

Further, according to the eighth invention, the transition condition that the hydraulic control for releasing the second engaging device is operating when the second engaging device is in the engaging transient state is satisfied. In this case, since it is determined that the second engaging device has been switched to the release transient state, the release transient state of the second engaging device can be appropriately determined.

Further, according to the ninth invention, it is possible to improve the accuracy of determining the operating state of the second engaging device in the hydraulic control for engaging or releasing the second engaging device.

It is a figure explaining the schematic structure of the vehicle to which this invention is applied, and also is the figure explaining the main part of the control function and the control system for various control in a vehicle. It is a figure for demonstrating the structure of a stepless speed change mechanism. It is a figure which shows an example for demonstrating the thrust necessary for shift control. It is a figure which shows an example of the relationship of each thrust at the time of t2 of FIG. It is a block diagram which shows the control structure for achieving both the target shift and the belt slip prevention with the minimum necessary thrust. It is a figure which shows an example of the thrust ratio map for calculating the thrust ratio used for the calculation of the thrust on the secondary pulley side. It is a figure which shows an example of the thrust ratio map for calculating the thrust ratio used for the calculation of the thrust on the primary pulley side. It is a figure which shows an example of the differential thrust map for calculating the secondary differential thrust. It is a figure which shows an example of the differential thrust map for calculating the primary differential thrust. It is a state transition diagram showing the relationship between the operating state of the second clutch represented by the four states of complete release, complete engagement, release transient, and engagement transient, and the transition condition for determining the switching of the operating state. .. It is a flowchart explaining the control operation for improving the determination accuracy of the operation state of the 2nd clutch, which is the main part of the control operation of an electronic control device.

In the embodiment of the present invention, the primary pulley which is the pulley on the input side and the secondary pulley which is the pulley on the output side are, for example, the groove width between the fixed sheave and the movable sheave and their fixed sheave and the movable sheave, respectively. It has the hydraulic actuator which applies a thrust for changing the above. The vehicle provided with the vehicle power transmission device includes a hydraulic control circuit that independently controls the pulley hydraulic pressure as the operating hydraulic pressure supplied to the hydraulic actuator. This hydraulic control circuit may be configured to result in pulley hydraulic pressure by, for example, controlling the flow rate of hydraulic oil to the hydraulic actuator. By controlling each thrust (= pulley hydraulic pressure × pressure receiving area) in the primary pulley and the secondary pulley by such a hydraulic pressure control circuit, the target shift can be realized while preventing the transmission element from slipping. The shift control is executed as follows. The transmission element wound between the primary pulley and the secondary pulley is an endless annular hoop and an element which is a thick plate piece-like block connected in a large number in the thickness direction along the hoop. An endless annular compression type transmission belt, or a tension type transmission belt in which the ends of alternately stacked link plates are connected to each other by connecting pins to form an endless annular link chain. The continuously variable transmission mechanism is a known belt-type continuously variable transmission. In a broad sense, the concept of this belt-type continuously variable transmission includes a chain-type continuously variable transmission.

Further, the power source is, for example, an engine such as a gasoline engine or a diesel engine that generates power by burning fuel. Further, the vehicle may be provided with an electric motor or the like as the power source in addition to or in place of the engine.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and is a diagram illustrating a main part of a control function and a control system for various controls in the vehicle 10. In FIG. 1, the vehicle 10 includes an engine 12 that functions as a power source, a drive wheel 14, and a vehicle power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheel 14. .. Hereinafter, the power transmission device 16 for a vehicle is referred to as a power transmission device 16.

The power transmission device 16 is connected to a known torque converter 20 as a fluid transmission device connected to the engine 12, an input shaft 22 connected to the torque converter 20, and an input shaft 22 in the case 18 as a non-rotating member. A gear mechanism connected to the input shaft 22 via the continuously variable transmission mechanism 24, a forward / backward switching device 26 also connected to the input shaft 22, and a gear mechanism provided in parallel with the continuously variable transmission mechanism 24. 28, deceleration consisting of a pair of gears that are provided on the output shaft 30, the counter shaft 32, the output shaft 30 and the counter shaft 32, which are common output rotating members of the continuously variable transmission mechanism 24 and the gear mechanism 28, and mesh with each other. The gear device 34, the gear 36 provided on the counter shaft 32 so as not to rotate relative to each other, the differential gear 38 connected to the gear 36, and the like are provided. Further, the power transmission device 16 includes left and right axles 40 connected to the differential gear 38. The input shaft 22 is an input rotating member to which the power of the engine 12 is transmitted. The output shaft 30 is an output rotating member that outputs the power of the engine 12 to the drive wheels 14. Unless otherwise specified, the above-mentioned power agrees with torque and force.

In the power transmission device 16 configured in this way, the power output from the engine 12 sequentially passes through the torque converter 20, the forward / backward switching device 26, the gear mechanism 28, the reduction gear device 34, the differential gear 38, the axle 40, and the like. , Is transmitted to the left and right drive wheels 14. Alternatively, in the power transmission device 16, the power output from the engine 12 is sequentially transmitted to the left and right drive wheels 14 via the torque converter 20, the continuously variable transmission mechanism 24, the reduction gear device 34, the differential gear 38, the axle 40, and the like. Will be done.

As described above, the power transmission device 16 includes a gear mechanism 28 and a continuously variable transmission mechanism 24 provided in parallel with the power transmission path PT between the engine 12 and the drive wheels 14. Specifically, the power transmission device 16 includes a gear mechanism 28 and a continuously variable transmission mechanism 24 provided in parallel with the power transmission path PT between the input shaft 22 and the output shaft 30. That is, the power transmission device 16 is provided in parallel between the input shaft 22 and the output shaft 30, and is capable of transmitting the power of the engine 12 from the input shaft 22 to the output shaft 30. It is equipped with. The plurality of power transmission paths include a first power transmission path PT1 via a gear mechanism 28 and a second power transmission path PT2 via a continuously variable transmission mechanism 24. That is, the power transmission device 16 includes a plurality of power transmission paths of the first power transmission path PT1 and the second power transmission path PT2 in parallel between the input shaft 22 and the output shaft 30. The first power transmission path PT1 is a power transmission path for transmitting the power of the engine 12 from the input shaft 22 to the drive wheels 14 via the gear mechanism 28. The second power transmission path PT2 is a power transmission path for transmitting the power of the engine 12 from the input shaft 22 to the drive wheels 14 via the continuously variable transmission mechanism 24.

In the power transmission device 16, the power transmission path for transmitting the power of the engine 12 to the drive wheels 14 is switched between the first power transmission path PT1 and the second power transmission path PT2 according to the traveling state of the vehicle 10. Therefore, the power transmission device 16 includes a plurality of engagement devices that selectively form the first power transmission path PT1 and the second power transmission path PT2. The plurality of engaging devices include a first clutch C1, a first brake B1, and a second clutch C2. The first clutch C1 is provided in the first power transmission path PT1 and is an engaging device that selectively connects or disconnects the first power transmission path PT1 and is engaged when moving forward. This is the first engaging device that forms the first power transmission path PT1. The first brake B1 is provided in the first power transmission path PT1 and is an engaging device that selectively connects or disconnects the first power transmission path PT1 and is engaged when moving backward. This is an engaging device that forms the first power transmission path PT1. The first power transmission path PT1 is formed by engaging the first clutch C1 or the first brake B1. The second clutch C2 is provided in the second power transmission path PT2, and is an engaging device for selectively connecting or disconnecting the second power transmission path PT2. 2 It is a second engaging device that forms the power transmission path PT2. The second power transmission path PT2 is formed by the engagement of the second clutch C2. The first clutch C1, the first brake B1, and the second clutch C2 are all known hydraulic wet friction engagement devices that are frictionally engaged by a hydraulic actuator. Each of the first clutch C1 and the first brake B1 is one of the elements constituting the forward / backward switching device 26, as will be described later.

The engine 12 includes an engine control device 42 having various devices necessary for output control of the engine 12, such as an electronic throttle device, a fuel injection device, and an ignition device. The engine 12 is an engine by controlling the engine control device 42 according to the accelerator operation amount θacc, which is the operation amount of the accelerator pedal corresponding to the drive request amount for the vehicle 10 by the driver, by the electronic control device 90 described later. The torque Te is controlled.

The torque converter 20 includes a pump impeller 20p connected to the engine 12 and a turbine impeller 20t connected to the input shaft 22. The power transmission device 16 includes a mechanical oil pump 44 connected to a pump impeller 20p. The oil pump 44 is rotationally driven by the engine 12 to control the speed change of the continuously variable transmission mechanism 24, generate a belt pinching pressure in the continuously variable transmission mechanism 24, and engage with each of the plurality of engaging devices. The main pressure of the hydraulic pressure for switching the operating state such as setting and releasing is supplied to the hydraulic control circuit 46 provided in the vehicle 10.

The forward / backward switching device 26 includes a double pinion type planetary gear device 26p, a first clutch C1, and a first brake B1. The planetary gear device 26p is a differential mechanism having three rotating elements of a carrier 26c as an input element, a sun gear 26s as an output element, and a ring gear 26r as a reaction force element. The carrier 26c is connected to the input shaft 22. The ring gear 26r is selectively coupled to the case 18 via the first brake B1. The sun gear 26s is connected to a small diameter gear 48 provided around the input shaft 22 so as to be rotatable relative to the input shaft 22 coaxially with the input shaft 22. The carrier 26c and the sun gear 26s are selectively connected via the first clutch C1.

The gear mechanism 28 is provided with a small diameter gear 48, a gear mechanism counter shaft 50, and a large diameter around the gear mechanism counter shaft 50 so as to be coaxially non-rotatable with respect to the gear mechanism counter shaft 50 and mesh with the small diameter gear 48. It is equipped with a gear 52. The large diameter gear 52 has a larger diameter than the small diameter gear 48. Further, the gear mechanism 28 is coaxial with the idler gear 54 provided around the gear mechanism counter shaft 50 so as to be rotatable relative to the gear mechanism counter shaft 50 and about the output shaft 30 with respect to the output shaft 30. It is provided with an output gear 56 that is provided in the center so as not to rotate relative to each other and meshes with the idler gear 54. The output gear 56 has a larger diameter than the idler gear 54. Therefore, in the gear mechanism 28, one gear stage is formed in the power transmission path PT between the input shaft 22 and the output shaft 30. The gear mechanism 28 is a gear mechanism having a gear stage. The gear mechanism 28 is further provided around the gear mechanism counter shaft 50 between the large diameter gear 52 and the idler gear 54, and meshes with which the power transmission path between them is selectively connected or disconnected. It is equipped with a formula clutch D1. The meshing clutch D1 is an engaging device that selectively connects or disconnects the first power transmission path PT1 and forms the first power transmission path PT1 by being engaged. be. The meshing clutch D1 is an engaging device that forms a first power transmission path PT1 by being engaged with the first clutch C1 or the first brake B1, and is included in the plurality of engaging devices. The operating state of the meshing clutch D1 is switched by the operation of a hydraulic actuator (not shown) provided in the power transmission device 16.

The first power transmission path PT1 is formed by engaging both the meshing clutch D1 and the first clutch C1 or the first brake B1 provided on the input shaft 22 side of the meshing clutch D1. .. The engagement of the first clutch C1 forms a power transmission path for forward movement, while the engagement of the first brake B1 forms a power transmission path for reverse movement. In the power transmission device 16, when the first power transmission path PT1 is formed, the power of the engine 12 can be transmitted from the input shaft 22 to the output shaft 30 via the gear mechanism 28. .. On the other hand, the first power transmission path PT1 is put into a neutral state in which power transmission is impossible when both the first clutch C1 and the first brake B1 are released or when the meshing clutch D1 is released.

FIG. 2 is a diagram for explaining the configuration of the continuously variable transmission mechanism 24. In FIGS. 1 and 2, in the stepless speed change mechanism 24, the primary shaft 58 provided coaxially with the input shaft 22 and integrally connected to the input shaft 22, and the effective diameter connected to the primary shaft 58 are variable. Is wound between the primary pulley 60, the secondary shaft 62 provided coaxially with the output shaft 30, the secondary pulley 64 with a variable effective diameter connected to the secondary shaft 62, and the pulleys 60 and 64, respectively. It is provided with a transmission belt 66 as a transmission element. The continuously variable transmission mechanism 24 is a known belt-type continuously variable transmission in which power is transmitted via frictional force between the pulleys 60 and 64 and the transmission belt 66, and the power of the engine 12 is driven by the drive wheels 14. Communicate to the side. The frictional force agrees with the pinching pressure, and is also referred to as a belt pinching pressure. This belt pinching pressure is the belt torque capacity Tcvt, which is the torque capacity of the transmission belt 66 in the continuously variable transmission mechanism 24.

The primary pulley 60 includes a fixed sheave 60a connected to the primary shaft 58, a movable sheave 60b provided so as to be non-rotatable relative to the axis of the primary shaft 58 and movable in the axial direction with respect to the fixed sheave 60a. It is provided with a hydraulic actuator 60c that applies a primary thrust Win to the movable sheave 60b. The primary thrust Win is the thrust (= primary pressure Pin × pressure receiving area) of the primary pulley 60 for changing the V-groove width between the fixed sheave 60a and the movable sheave 60b. That is, the primary thrust Win is the thrust of the primary pulley 60 that clamps the transmission belt 66 applied by the hydraulic actuator 60c. The primary pressure Pin is the hydraulic pressure supplied to the hydraulic actuator 60c by the hydraulic control circuit 46, and is the pulley hydraulic pressure that produces the primary thrust Win. Further, the secondary pulley 64 has a fixed sheave 64a connected to the secondary shaft 62 and a movable sheave 64b provided so as to be non-rotatable and movable in the axial direction of the secondary shaft 62 with respect to the fixed sheave 64a. And a hydraulic actuator 64c that applies a secondary thrust Wout to the movable sheave 64b. The secondary thrust Wout is the thrust (= secondary pressure Pout × pressure receiving area) of the secondary pulley 64 for changing the V-groove width between the fixed sheave 64a and the movable sheave 64b. That is, the secondary thrust Wout is the thrust of the secondary pulley 64 that clamps the transmission belt 66 applied by the hydraulic actuator 64c. The secondary pressure Pout is the hydraulic pressure supplied to the hydraulic actuator 64c by the hydraulic control circuit 46, and is the pulley hydraulic pressure that causes the secondary thrust Wout.

In the continuously variable transmission mechanism 24, the primary pressure Pin and the secondary pressure Pout are controlled by the hydraulic control circuit 46 driven by the electronic control device 90 described later, so that the primary thrust Win and the secondary thrust Wout are controlled respectively. To. As a result, in the continuously variable transmission mechanism 24, the V-groove width of each of the pulleys 60 and 64 changes, the hooking diameter (= effective diameter) of the transmission belt 66 is changed, and the gear ratio γcvt (= primary rotation speed Npri / secondary rotation) The speed Nsec) is changed, and the belt pinching pressure is controlled so that the transmission belt 66 does not slip. That is, by controlling each of the primary thrust Win and the secondary thrust Wout, the gear ratio γcvt of the continuously variable transmission mechanism 24 is set as the target gear ratio γcvttgt while the belt slip, which is the slip of the transmission belt 66, is prevented. The primary rotation speed Npri is the rotation speed of the primary shaft 58, and the secondary rotation speed Nsec is the rotation speed of the secondary shaft 62.

In the continuously variable transmission mechanism 24, when the primary pressure Pin is increased, the V-groove width of the primary pulley 60 is narrowed and the gear ratio γcvt is reduced. The reduction of the gear ratio γcvt means that the continuously variable transmission mechanism 24 is upshifted. In the continuously variable transmission mechanism 24, the highest gear ratio γmin is formed where the V-groove width of the primary pulley 60 is minimized. The highest gear ratio γmin is the gear ratio γcvt on the highest vehicle speed side, which is the highest vehicle speed side in the range of the gear ratio γcvt that can be formed by the continuously variable transmission mechanism 24, and the gear ratio γcvt is the smallest value. The minimum gear ratio. On the other hand, in the continuously variable transmission mechanism 24, when the primary pressure Pin is lowered, the V-groove width of the primary pulley 60 is widened and the gear ratio γcvt is increased. Increasing the gear ratio γcvt means that the continuously variable transmission mechanism 24 is downshifted. In the continuously variable transmission mechanism 24, the lowest gear ratio γmax is formed where the V-groove width of the primary pulley 60 is maximized. The lowest gear ratio γmax is the gear ratio γcvt on the lowest vehicle speed side, which is the lowest vehicle speed side in the range of the gear ratio γcvt that can be formed by the continuously variable transmission mechanism 24, and the gear ratio γcvt is the largest value. Maximum gear ratio. In the continuously variable transmission mechanism 24, the belt slip is prevented by the primary thrust Win and the secondary thrust Wout, and the target gear ratio γcvttgt is realized by the mutual relationship between the primary thrust Win and the secondary thrust Wout. The target shift cannot be achieved with only one thrust. As will be described later, in the mutual relationship between the primary pressure Pin and the secondary pressure Pout, the thrust ratio τ (= Wout / Win), which is the value of the ratio between the primary thrust Win and the secondary thrust Wout, is changed to cause stepless speed change. The gear ratio γcvt of the mechanism 24 is changed. The thrust ratio τ is the value of the ratio of the secondary thrust Wout to the primary thrust Win. For example, as the thrust ratio τ increases, the gear ratio γcvt increases, that is, the stepless speed change mechanism 24 is downshifted.

The output shaft 30 is arranged so as to be rotatable relative to the secondary shaft 62 in a coaxial center. The second clutch C2 is provided in the power transmission path between the secondary pulley 64 and the output shaft 30. The second power transmission path PT2 is formed by engaging the second clutch C2. In the power transmission device 16, when the second power transmission path PT2 is formed, the power of the engine 12 can be transmitted from the input shaft 22 to the output shaft 30 via the stepless speed change mechanism 24. Will be done. On the other hand, the second power transmission path PT2 is put into the neutral state when the second clutch C2 is released. The gear ratio γcvt of the continuously variable transmission mechanism 24 corresponds to the gear ratio in the second power transmission path PT2.

In the power transmission device 16, the shift ratio EL of the gear mechanism 28, which is the shift ratio γ gear (= input shaft rotation speed Nin / output shaft rotation speed Nout) in the first power transmission path PT1, is the maximum shift in the second power transmission path PT2. It is set to a value larger than the lowest speed change ratio γmax of the stepless speed change mechanism 24, which is a ratio. That is, the gear ratio EL is set to the gear ratio on the low side of the gear ratio γmax on the lowest side. The gear ratio EL of the gear mechanism 28 corresponds to the first speed gear ratio γ1 in the power transmission device 16, and the lowest gear ratio γmax of the continuously variable transmission mechanism 24 corresponds to the second speed gear ratio γ2 in the power transmission device 16. Equivalent to. In this way, the second power transmission path PT2 is formed with a gear ratio on the higher side than the first power transmission path PT1. The input shaft rotation speed Nin is the rotation speed of the input shaft 22, and the output shaft rotation speed Nout is the rotation speed of the output shaft 30.

In the vehicle 10, it is possible to selectively perform traveling in the gear traveling mode and traveling in the belt traveling mode. The gear traveling mode is a traveling mode in which the vehicle travels using the first power transmission path PT1 and is in a state where the first power transmission path PT1 is formed in the power transmission device 16. The belt traveling mode is a traveling mode in which the vehicle travels using the second power transmission path PT2, and is a traveling mode in which the second power transmission path PT2 is formed in the power transmission device 16. In the gear traveling mode, the first clutch C1 and the meshing clutch D1 are engaged and the second clutch C2 and the first brake B1 are released when the forward traveling is possible. In the gear traveling mode, the first brake B1 and the meshing clutch D1 are engaged and the second clutch C2 and the first clutch C1 are released when the reverse traveling is possible. In the belt traveling mode, the second clutch C2 is engaged and the first clutch C1 and the first brake B1 are released. In this belt running mode, forward running is possible.

The gear travel mode is selected in a relatively low vehicle speed region, including when the vehicle is stopped. The belt travel mode is selected in a relatively high vehicle speed region including a medium vehicle speed region. The meshing clutch D1 is engaged in the belt travel mode in the medium vehicle speed region of the belt travel mode, while the mesh clutch D1 is released in the belt travel mode in the high vehicle speed region of the belt travel mode. .. The meshing clutch D1 is released in the belt traveling mode in the high vehicle speed region, for example, by eliminating the drag of the gear mechanism 28 or the like during traveling in the belt traveling mode, and at high vehicle speed, the gear mechanism 28 or the planetary gear device. This is to prevent the 26p component, for example, a pinion, from rotating at a high speed.

The vehicle 10 includes an electronic control device 90 as a controller including a control device for the power transmission device 16. The electronic control device 90 includes, for example, a so-called microcomputer provided with a CPU, RAM, ROM, an input / output interface, etc., and the CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. The electronic control device 90 is an output control of the engine 12, a shift control of the continuously variable transmission mechanism 24, a belt pinching pressure control, and a hydraulic control for switching the operating state of each of the plurality of engaging devices (C1, B1, C2, D1). And so on. The electronic control device 90 is separately configured for engine control, hydraulic control, and the like, if necessary.

The electronic control device 90 includes various sensors provided in the vehicle 10 (for example, various rotational speed sensors 70, 72, 74, 76, accelerator operation amount sensor 78, throttle opening sensor 80, shift position sensor 82, etc.). Detection signal, etc. (for example, engine rotation speed Ne, primary rotation speed Npri equal to input shaft rotation speed Nin, secondary rotation speed Nsec, output shaft rotation speed Nout corresponding to vehicle speed V, magnitude of driver's acceleration operation The accelerator operation amount θacc, the throttle opening tap, the operation position POSsh of the shift lever 84 provided in the vehicle 10, etc.) are supplied respectively. Further, from the electronic control device 90, various command signals (for example, engine control command signal Se for controlling the engine 12) are transmitted to each device (for example, engine control device 42, hydraulic control circuit 46, etc.) provided in the vehicle 10. The hydraulic control command signal Scvt for controlling the speed change of the speed change mechanism 24, the belt pinching pressure, etc., the hydraulic control command signal Scbd for controlling the operating state of each of the plurality of engaging devices, etc.) are output respectively. Ru. The input shaft rotation speed Nin (= primary rotation speed Npri) is also the turbine rotation speed, the primary rotation speed Npri is also the rotation speed of the primary pulley 60, and the secondary rotation speed Nsec is the rotation speed of the secondary pulley 64. But it is also. Further, the electronic control device 90 calculates the actual gear ratio γcvt (= Npri / Nsec), which is the actual gear ratio γcvt of the continuously variable transmission mechanism 24, based on the primary rotation speed Npri and the secondary rotation speed Nsec.

The operation position POSsh of the shift lever 84 is, for example, a P, R, N, D operation position. The P operation position is a parking operation position for selecting the P position of the power transmission device 16 in which the power transmission device 16 is in the neutral state and the output shaft 30 is mechanically fixed so as not to rotate. The neutral state of the power transmission device 16 is realized, for example, by releasing the first clutch C1, the first brake B1, and the second clutch C2. That is, the neutral state of the power transmission device 16 is a state in which neither the first power transmission path PT1 nor the second power transmission path PT2 is formed. The R operation position is a reverse travel operation position that selects the R position of the power transmission device 16 that enables reverse travel in the gear travel mode. The N operation position is a neutral operation position that selects the N position of the power transmission device 16 in which the power transmission device 16 is in the neutral state. The D operation position is the D of the power transmission device 16 that enables forward traveling in the gear traveling mode or by executing automatic transmission control of the continuously variable transmission mechanism 24 in the belt traveling mode. It is a forward running operation position that selects a position.

The electronic control device 90 includes an engine control means, that is, an engine control unit 92, and a shift control means, that is, a shift control unit 94, in order to realize various controls in the vehicle 10.

The engine control unit 92 applies the accelerator operation amount θacc and the vehicle speed V to, for example, a driving force map, which is a relationship that is experimentally or designedly obtained and stored, that is, a predetermined relationship, so that the target driving force Fwtgt Is calculated. The engine control unit 92 sets a target engine torque Tetgt from which the target driving force Fwtgt can be obtained, and outputs an engine control command signal Se that controls the engine 12 so that the target engine torque Tetgt can be obtained to the engine control device 42. ..

When the operation position POSsh is the P operation position or the N operation position while the vehicle is stopped, the shift control unit 94 is a hydraulic control command signal that engages the meshing clutch D1 in preparation for the transition to the gear traveling mode. Scbd is output to the hydraulic control circuit 46. When the operation position POSsh is changed from the P operation position or the N operation position to the D operation position while the vehicle is stopped, the shift control unit 94 sends the hydraulic control command signal Scbd that engages the first clutch C1 to the hydraulic control circuit 46. Output. As a result, the traveling mode is shifted to the gear traveling mode that enables forward traveling. When the operation position POSsh is changed from the P operation position or the N operation position to the R operation position while the vehicle is stopped, the shift control unit 94 sends the hydraulic control command signal Scbd that engages the first brake B1 to the hydraulic control circuit 46. Output. As a result, the traveling mode is shifted to the gear traveling mode that enables reverse traveling.

When the operation position POSsh is the D operation position, the shift control unit 94 executes switching control for switching between the gear travel mode and the belt travel mode. Specifically, the shift control unit 94 corresponds to the first speed shift stage corresponding to the shift ratio EL of the gear mechanism 28 in the gear travel mode and the lowest gear ratio γmax of the continuously variable transmission mechanism 24 in the belt travel mode. The vehicle speed V and the accelerator operation amount θacc are applied to the upshift line and the downshift line as the stepped shift map, which has a predetermined relationship and has a predetermined hysteresis for switching to the second speed shift stage. By doing so, the necessity of shifting is determined, and the driving mode is switched based on the determination result.

When the shift control unit 94 determines upshift while traveling in the gear traveling mode and switches to the belt traveling mode, the clutch that releases the first clutch C1 and re-grasps the clutch so as to engage the second clutch C2. The hydraulic control command signal Scbd for shifting the clutch is output to the hydraulic control circuit 46. As a result, the power transmission path PT in the power transmission device 16 is switched from the first power transmission path PT1 to the second power transmission path PT2. As described above, the shift control unit 94 changes from the gear traveling mode in which the first power transmission path PT1 is formed by the stepped shift control by the release of the first clutch C1 and the engagement of the second clutch C2. 2 The upshift of the power transmission device 16 for switching to the belt traveling mode in which the power transmission path PT2 is formed is executed. In this embodiment, the upshift of the power transmission device 16 for switching from the gear traveling mode to the belt traveling mode is referred to as a stepped upshift.

When the shift control unit 94 determines the downshift while traveling in the belt traveling mode and switches to the gear traveling mode, the clutch that releases the second clutch C2 and re-grasps the clutch so as to engage the first clutch C1. The hydraulic control command signal Scbd for shifting the clutch is output to the hydraulic control circuit 46. As a result, the power transmission path PT in the power transmission device 16 is switched from the second power transmission path PT2 to the first power transmission path PT1. As described above, the shift control unit 94 changes from the belt traveling mode in which the second power transmission path PT2 is formed by the stepped shift control by the release of the second clutch C2 and the engagement of the first clutch C1. 1 The downshift of the power transmission device 16 for switching to the gear traveling mode in which the power transmission path PT1 is formed is executed. In this embodiment, the downshift of the power transmission device 16 that switches from the belt traveling mode to the gear traveling mode is referred to as a stepped downshift.

In the switching control for switching between the gear traveling mode and the belt traveling mode, the torque is transferred by the clutch-to-clutch shift by passing through the state of the belt traveling mode in the medium vehicle speed region in which the meshing clutch D1 is engaged. Since the first power transmission path PT1 and the second power transmission path PT2 are switched only by this, the switching shock is suppressed.

In the belt traveling mode, the shift control unit 94 sets the primary pressure Pin and the secondary pressure Pout so as to achieve the target shift ratio γcvttgt of the continuously variable transmission mechanism 24 while preventing the belt slip of the continuously variable transmission mechanism 24. The hydraulic pressure control command signal Scvt that controls the above is output to the hydraulic pressure control circuit 46, and the continuously variable transmission mechanism 24 is changed. The hydraulic pressure control command signal Scvt is a primary instruction pressure Spin for setting the primary pressure Pin as the target primary pressure Pintgt, and a secondary instruction pressure Spout for setting the secondary pressure Pout as the target secondary pressure Pouttgt.

The target primary pressure Pintgt is a target value of the primary pressure Pin that causes the target thrust of the primary pulley 60, that is, the target value of the primary thrust Win, which is the target value of the primary target thrust Wintgt. The target secondary pressure Pouttgt is a target value of the secondary pressure Pout that causes a secondary target thrust Wouttgt, which is a target value of the target thrust of the secondary pulley 64, that is, the secondary thrust Wout. In the calculation of the primary target thrust Wintgt and the secondary target thrust Wouttgt, the required thrust, which is the thrust required to prevent the belt slip of the continuously variable transmission mechanism 24 with the minimum necessary thrust, is taken into consideration. This required thrust is the belt slip limit thrust Wlmt, which is the thrust immediately before the belt slip of the continuously variable transmission mechanism 24 occurs. In this embodiment, the belt slip limit thrust Wlmt is referred to as a slip limit thrust Wlmt.

Specifically, the shift control unit 94 calculates the primary target thrust Wintgt and the secondary target thrust Wouttgt, respectively. The shift control unit 94 has a secondary thrust Wout calculated based on the primary side slip limit thrust Winlmt, which is the slip limit thrust Wlmt in the primary pulley 60, and a secondary side, which is the slip limit thrust Wlmt in the secondary pulley 64, as the secondary target thrust Wouttgt. Select the larger thrust of the slip limit thrust Woutlmt. The secondary thrust Wout calculated based on the primary side slip limit thrust Winlmt is the secondary side shift control thrust Woutsh, which is the thrust required for shift control on the secondary pulley 64 side, as will be described later.

The shift control unit 94 sets the primary thrust Win calculated based on the secondary target thrust Wouttgt as the primary target thrust Wintgt. The primary thrust Win calculated based on the secondary target thrust Wouttgt is the primary side shift control thrust Winsh, which is the thrust required for shift control on the primary pulley 60 side, as will be described later. Further, as will be described later, the shift control unit 94 controls the primary shift control thrust by feedback control of the primary thrust Win based on the shift ratio deviation Δγcvt (= γcvttgt−γcvt) between the target shift ratio γcvttgt and the actual shift ratio γcvt. Correct Winsh, that is, correct the primary target thrust Wintgt.

In the correction of the shift control thrust Winsh on the primary side described above, the deviation between the target value and the actual value in the parameter corresponding to the shift ratio γcvt and 1: 1 may be used instead of the shift ratio deviation Δγcvt. For example, in the correction of the shift control thrust Winsh on the primary side, the deviation ΔXin (= Xintgt-Xin) between the target pulley position Xintgt and the actual pulley position Xin (see FIG. 2) in the primary pulley 60 and the target pulley position Xouttgt in the secondary pulley 64. Deviation ΔXout (= Xouttgt-Xout) from the actual pulley position Xout (see FIG. 2), deviation ΔRin (= Rintgt-Rin) between the target belt hanging diameter Rintgt and the actual belt hanging diameter Rin (see FIG. 2) in the primary pulley 60. , Deviation ΔRout (= Routtgt-Rout) between the target belt hanging diameter Routtgt and the actual belt hanging diameter Rout (see FIG. 2) in the secondary pulley 64, Deviation ΔNpri (= Npritgt) between the target primary rotation speed Npritgt and the actual primary rotation speed Npri. -Npri) and the like can be used.

The thrust required for the shift control described above is the thrust required to realize the target shift, and is the thrust required to achieve the target gear ratio γcvttgt and the target shift speed dγtgt. The shift speed dγ is, for example, the amount of change (= dγcvt / dt) of the shift ratio γcvt per unit time. In this embodiment, the shift speed dγ is defined as the pulley position movement amount (= dX / dNelm) per element of the transmission belt 66. “DX” is the amount of axial displacement of the pulley [mm / ms] per unit time, and “dNelm” is the number of elements [pieces / ms] that bite into the pulley per unit time. The shift speed dγ is represented by a primary shift speed dγin (= dXin / dNelmin) and a secondary shift speed dγout (= dXout / dNelmout).

Specifically, the thrust of each of the pulleys 60 and 64 in a steady state in which the gear ratio γcvt is constant is referred to as a balanced thrust Wbl. Balanced thrust Wbl is also a steady thrust. The balanced thrust Wbl of the primary pulley 60 is the primary balanced thrust Winbl, the balanced thrust Wbl of the secondary pulley 64 is the secondary balanced thrust Woutbl, and these ratios are the thrust ratio τ (= Woutbl / Winbl). On the other hand, when a certain thrust is added or subtracted to any of the thrusts of the pulleys 60 and 64 in the steady state, the steady state collapses and the gear ratio γcvt changes, and the magnitude of the added or subtracted thrust is obtained. The shift speed dγ corresponding to the above is generated. This added or subtracted thrust is referred to as a shift difference thrust ΔW. Hereinafter, the shift difference thrust ΔW is referred to as a differential thrust ΔW. The differential thrust ΔW is also a transient thrust. The differential thrust ΔW when the target shift is realized on the primary pulley 60 side is the primary differential thrust ΔWin as the differential thrust ΔW converted on the primary pulley 60 side. The differential thrust ΔW when the target shift is realized on the secondary pulley 64 side is the secondary differential thrust ΔWout as the differential thrust ΔW converted to the secondary pulley 64 side.

The thrust required for the above-mentioned shift control is to realize the target shift ratio γcvttgt corresponding to one thrust based on the thrust ratio τ for maintaining the target shift ratio γcvttgt when one thrust is set. It is the sum of the other balanced thrust Wbl and the differential thrust ΔW for realizing the target shift speed dγtgt when the target shift ratio γcvttgt is changed. The target shift speed dγtgt is represented by a primary target shift speed dγintgt and a secondary target shift speed dγouttgt. The primary differential thrust ΔWin has a positive value exceeding zero, that is, “ΔWin> 0” in the upshift state, and a negative value less than zero, that is, “ΔWin <0” in the downshift state. If so, it becomes zero, that is, “ΔWin = 0”. Further, the secondary difference thrust ΔWout has a negative value less than zero, that is, “ΔWout <0” in the upshift state, and a positive value exceeding zero, that is, “ΔWout> 0” in the downshift state, and the gear ratio is constant. In the steady state, it becomes zero, that is, "ΔWout = 0".

FIG. 3 is a diagram for explaining the thrust required for the shift control described above. FIG. 4 is a diagram showing an example of the relationship between each thrust at the time point t2 in FIG. 3 and 4 show the primary set when the target upshift is realized on the primary pulley 60 side when the secondary thrust Wout is set so as to prevent the belt slip on the secondary pulley 64 side, for example. An example of thrust Win is shown. In FIG. 3, since the target gear ratio γcvttgt is in a constant steady state and ΔWin = 0 before the time t1 or after the time t3, the primary thrust Win is only the primary balance thrust Winbl (= Wout / τ). Since the target gear ratio γcvttgt is reduced in the upshift state from the time point t1 to the time point t3, the primary thrust Win is the sum of the primary balance thrust Winbl and the primary differential thrust ΔWin as shown in FIG. The shaded portion of each thrust shown in FIG. 4 corresponds to each balanced thrust Wbl for maintaining the target gear ratio γcvttgt at t2 in FIG.

FIG. 5 is a block diagram showing a control structure for achieving both target shifting and belt slip prevention with the minimum necessary thrust, and is a diagram illustrating hydraulic control, that is, CVT hydraulic control in the continuously variable transmission mechanism 24. be.

In FIG. 5, the shift control unit 94 calculates the target gear ratio γcvttgt. Specifically, the shift control unit 94 calculates the target primary rotation speed Npritgt by applying the accelerator operation amount θacc and the vehicle speed V to, for example, the CVT shift map, which has a predetermined relationship. The shift control unit 94 calculates the post-shift target shift ratio γcvttgtl (= Npritgt / Nsec), which is the shift ratio γcvt to be achieved after shifting of the continuously variable transmission mechanism 24, based on the target primary rotation speed Npritgt. The shift control unit 94 is shifting based on the shift ratio γcvt before the start of the shift, the target shift ratio γcvttgtl after the shift, and their differences, for example, in a predetermined relationship so as to realize a quick and smooth shift. The target gear ratio γcvttgt is determined as the target value of the transient gear ratio γcvt. For example, the shift control unit 94 determines the target shift ratio γcvttgt to be changed during the shift as a function of the elapsed time that changes along a smooth curve that changes from the start of the shift toward the target shift ratio γcvttgtl after the shift. This smooth curve is, for example, a first-order lag curve or a second-order lag curve. When the shift control unit 94 determines the target shift ratio γcvttgt, the shift control unit 94 calculates the target shift speed dγtgt during shifting based on the target shift ratio γcvttgt. When the shift is completed and the target shift ratio γcvttgt becomes a constant steady state, the target shift speed dγtgt is set to zero.

The shift control unit 94 calculates the input torque to the continuously variable transmission mechanism 24 used for calculating the primary target thrust Wintgt and the secondary target thrust Wouttgt. The input torque to the stepless speed change mechanism 24 is the belt input torque Tb1 for calculating the thrust ratio as the first input torque used for calculating the thrust ratio τ that realizes the target speed change ratio γcvttgt of the stepless speed change mechanism 24, and It is a belt input torque Tb2 for preventing belt slip as a second input torque used for each calculation of the primary side slip limit thrust Winlmt and the secondary side slip limit thrust Woutlmt. In this embodiment, the belt input torque Tb1 for calculating the thrust ratio is referred to as the input torque Tb1 for calculating the thrust ratio, and the belt input torque Tb2 for preventing the belt slip is referred to as the input torque Tb2 for preventing the belt slip.

Specifically, the shift control unit 94 calculates the estimated value of the engine torque Te by applying the throttle opening tap and the engine rotation speed Ne to, for example, the engine torque map, which is a predetermined relationship. The shift control unit 94 calculates the turbine torque Tt based on the estimated value of the engine torque Te and, for example, the characteristics of the torque converter 20 which is a predetermined relationship. This turbine torque Tt is an estimated value of the input torque to the continuously variable transmission mechanism 24. The shift control unit 94 uses this turbine torque Tt as the input torque Tb1 for calculating the thrust ratio.

As the input torque Tb2 for belt slip prevention, basically, the input torque Tb1 for calculating the thrust ratio may be used. However, it is not preferable that the slip limit thrust Wlmt is set to zero when the input torque Tb1 for calculating the thrust ratio is zero, in consideration of variations and the like. Therefore, as the belt slip prevention input torque Tb2, a torque to which a lower limit guard process is applied to the absolute value of the thrust ratio calculation input torque Tb1 is used. The shift control unit 94 selects, as the belt slip prevention input torque Tb2, the larger of the absolute value of the thrust ratio calculation input torque Tb1 and the minimum guaranteed torque Tblim. This minimum guaranteed torque Tblim is, for example, a predetermined lower limit torque for increasing the belt slip prevention input torque Tb2 to the safe side in consideration of variation in order to prevent belt slip, and is a positive torque. .. When the input torque Tb1 for calculating the thrust ratio is a negative value, considering that the torque accuracy is low, a predetermined torque corresponding to the input torque Tb1 for calculating the thrust ratio is used as the input torque Tb2 for preventing belt slippage. May be done. This predetermined torque is, for example, a torque having a positive value predetermined as a value larger than the absolute value of the input torque Tb1 for calculating the thrust ratio. As described above, the belt slip prevention input torque Tb2 is a torque based on the thrust ratio calculation input torque Tb1.

In the block B1 and the block B2 of FIG. 5, the shift control unit 94 calculates the slip limit thrust Wlmt based on the actual shift ratio γcvt and the belt slip prevention input torque Tb2. Specifically, the shift control unit 94 calculates the secondary side slip limit thrust Woutlmt using the following equation (1). The shift control unit 94 calculates the primary side slip limit thrust Winlmt using the following equation (2). In the following equations (1) and (2), "Tb2" is the belt slip prevention input torque Tb2, and "Tout" is the belt slip prevention input torque Tb2 converted to the secondary pulley 64 side (= γcvt × Tb2). = (Rout / Rin) × Tb2), “α” is the sheave angle of each pulley 60, 64, “μin” is the coefficient of friction between a predetermined element and the pulley in the primary pulley 60, and “μout” is the predetermined coefficient in the secondary pulley 64. The coefficient of friction between the element and the pulley, "Rin" is the belt hook diameter in the primary pulley 60 uniquely calculated from the actual gear ratio γcvt, and "Rout" is the belt in the secondary pulley 64 uniquely calculated from the actual gear ratio γcvt. The coefficient of friction (see FIG. 2).

Woutlmt = (Tout × cosα) / (2 × μout × Rout)
= (Tb2 × cosα) / (2 × μout × Rin)… (1)
Winlmt = (Tb2 x cosα) / (2 x μin x Rin) ... (2)

As the slip limit thrust Wlmt, for example, a value obtained by subjecting the calculated slip limit thrust Wlmt to a lower limit guard process may be used. The shift control unit 94 has, for example, as the primary side slip limit thrust Winlmt used in the block B3 of FIG. 5, the larger of the primary side slip limit thrust Winlmt calculated by using the above equation (2) and the primary side minimum thrust Winmin. Select one thrust. The primary-side minimum thrust Winmin is the hard limit minimum thrust of the primary pulley 60, including the thrust generated by the control variation of the primary pressure Pin and the thrust generated by the centrifugal hydraulic pressure in the hydraulic actuator 60c. The control variation of the primary pressure Pin is a predetermined primary that may be supplied from the hydraulic control circuit 46 to the hydraulic actuator 60c even if the primary instruction pressure Spin having the primary pressure Pin of zero is output. This is the maximum value of the pressure Pin. The same applies to the secondary side slip limit thrust Woutlmt.

In the block B3 and the block B6 of FIG. 5, the shift control unit 94 calculates the balance thrust Wbl. That is, the shift control unit 94 calculates the secondary balance thrust Woutbl for the primary side slip limit thrust Winlmt and the primary balance thrust Winbl for the secondary target thrust Wouttgt, respectively.

Specifically, the shift control unit 94 applies the target gear ratio γcvttgt and the inverse number SFin ^-1 of the primary safety factor SFin to the thrust ratio map map (τin) as shown in FIG. 6, for example, to achieve the target gear ratio. Calculate the thrust ratio τin that realizes γcvttgt. The thrust ratio map map (τin) is a diagram showing an example of the relationship between the reciprocal SFin ^-1 of the primary safety factor and the thrust ratio τin, which are predetermined with the target gear ratio γcvttgt as a parameter. The thrust ratio τin is a thrust ratio for calculating the secondary thrust as a thrust ratio used when calculating the thrust on the secondary pulley 64 side based on the thrust on the primary pulley 60 side. The shift control unit 94 calculates the secondary balance thrust Woutbl based on the primary side slip limit thrust Winlmt and the thrust ratio τin using the following equation (3). The primary safety factor SFin is, for example, "Win / Winlmt" or "Tb2 / Tb1", and the reciprocal SFin ^-1 of the primary safety factor is, for example, "Winlmt / Win" or "Tb1 / Tb2". be. Further, the shift control unit 94 realizes the target shift ratio γcvttgt by applying the target shift ratio γcvttgt and the inverse number SFout ^-1 of the secondary safety factor SFout to the thrust ratio map map (τout) as shown in FIG. 7, for example. Calculate the thrust ratio τout. The thrust ratio map map (τout) is a diagram showing an example of the relationship between the reciprocal SFout ^-1 of the secondary safety factor and the thrust ratio τout, which are predetermined with the target gear ratio γcvttgt as a parameter. The thrust ratio τout is a thrust ratio for calculating the primary thrust as a thrust ratio used when calculating the thrust on the primary pulley 60 side based on the thrust on the secondary pulley 64 side. The shift control unit 94 calculates the primary balance thrust Winbl based on the secondary target thrust Wouttgt and the thrust ratio τout using the following equation (4). The secondary safety factor SFout is, for example, "Wout / Woutlmt" or "Tb2 / Tb1", and the reciprocal SFout ^-1 of the secondary safety factor is, for example, "Woutlmt / Wout" or "Tb1 / Tb2". be. Since the input torque Tb2 for belt slip prevention is always a positive value, the reciprocals SFin ^-1 and SFout of the above safety factors are used when the vehicle 10 is in a driving state where the input torque Tb1 for thrust ratio calculation is a positive value. Since ^-1 is also a positive value, the value in the drive region is used as the thrust ratio τ. On the other hand, when the vehicle 10 in which the input torque Tb1 for calculating the thrust ratio has a negative value is in the driven state, the reciprocals SFin ^-1 and SFout ^-1 of the above safety factors also have negative values, so that the thrust ratio τ is The value of the driven region is used. The reciprocals SFin ^-1 and SFout ^-1 may be calculated each time the balance thrust Wbl is calculated, but if the safety factors SFin -1 and SFout are set to predetermined values (for example, about 1-1.5), respectively. If so, the reciprocal of it may be set.

Woutbl ＝ Winlmt × τin… (3)
Winbl = Wouttgt / τout… (4)

As described above, the slip limit thrust Winlmt and Woutlmt are calculated based on the belt slip prevention input torque Tb2 based on the thrust ratio calculation input torque Tb1. The reciprocals SFin ^-1 and SFout ^-1 of the above safety factors, which are the basis for calculating the thrust ratios τin and τout, are values based on the input torque Tb1 for calculating the thrust ratio. Therefore, the shift control unit 94 calculates the thrust ratio τ that realizes the target shift ratio γcvttgt of the continuously variable transmission mechanism 24 based on the input torque Tb1 for calculating the thrust ratio.

In the block B4 and the block B7 of FIG. 5, the shift control unit 94 calculates the differential thrust ΔW. That is, the shift control unit 94 calculates the secondary differential thrust ΔWout and the primary differential thrust ΔWin.

Specifically, the shift control unit 94 calculates the secondary differential thrust ΔWout by applying the secondary target shift speed dγouttgt to the differential thrust map (ΔWout) as shown in FIG. 8, for example. The differential thrust map map (ΔWout) is a diagram showing an example of the relationship between the predetermined secondary shift speed dγout and the secondary differential thrust ΔWout. The shift control unit 94 calculates the secondary shift control thrust Woutsh (= Woutbl + ΔWout) by adding the secondary differential thrust ΔWout to the secondary balance thrust Woutbl as the secondary thrust required to prevent the belt slip on the primary pulley 60 side. Further, the shift control unit 94 calculates the primary differential thrust ΔWin by applying the primary target shift speed dγintgt to the differential thrust map (ΔWin) as shown in FIG. 9, for example. The differential thrust map map (ΔWin) is a diagram showing an example of the relationship between the predetermined primary shift speed dγin and the primary differential thrust ΔWin. The shift control unit 94 calculates the primary shift control thrust Winsh (= Winbl + ΔWin) by adding the primary differential thrust ΔWin to the primary balance thrust Winbl.

In the calculation in the blocks B3 and B4, a predetermined physical characteristic diagram such as a thrust ratio map map (τin) as shown in FIG. 6 and a differential thrust map map (ΔWout) as shown in FIG. 8 is used. Therefore, there are variations in the physical characteristics in the calculation results of the secondary balance thrust Woutbl and the secondary differential thrust ΔWout due to individual differences in the hydraulic control circuit 46 and the like. Therefore, when considering such variations in physical characteristics, the shift control unit 94 may add the control margin Wmgn to the primary side slip limit thrust Winlmt. The control margin Wmgn is a predetermined predetermined thrust corresponding to the variation in the physical characteristics related to the calculation of the secondary balance thrust Woutbl and the secondary differential thrust ΔWout. When considering the variation in the physical characteristics as described above, the shift control unit 94 uses the equation “Woutbl ＝ (Winlmt + Wmgn) × τin” shown in FIG. 5 instead of the equation (3) to be secondary. Calculate the balance thrust Woutbl. The variation in the physical characteristics is different from the variation in the actual pulley hydraulic pressure with respect to the hydraulic control command signal Scvt. The variation in the pulley hydraulic pressure is a relatively large value depending on the hard unit such as the hydraulic control circuit 46, but the variation in the physical characteristics is an extremely small value as compared with the variation in the pulley hydraulic pressure.

In block B5 of FIG. 5, the shift control unit 94 selects the larger thrust of the secondary side slip limit thrust Woutlmt and the secondary side shift control thrust Woutsh as the secondary target thrust Wouttgt.

In the block B8 of FIG. 5, the shift control unit 94 calculates the feedback control amount Winfb. Specifically, the shift control unit 94 uses a predetermined feedback control formula as shown in the following equation (5), for example, to match the actual shift ratio γcvt with the target shift ratio γcvttgt (feedback control amount). = FB control amount) Calculate Winfb. In the following equation (5), "Δγcvt" is a gear ratio deviation Δγcvt, "Kp" is a predetermined proportionality constant, "Ki" is a predetermined integral constant, and "Kd" is a predetermined differential constant. The shift control unit 94 calculates the value (= Winsh + Winbb) after correcting the primary shift control thrust Winsh by feedback control by adding the feedback control amount Winfb to the primary shift control thrust Winsh as the primary target thrust Wintgt. ..

Winfb ＝ Kp × Δγcvt ＋ Ki × (∫Δγcvtdt) ＋ Kd × (dΔγcvt / dt)… (5)

In the block B9 and the block B10 of FIG. 5, the shift control unit 94 converts the target thrust into the target pulley pressure. Specifically, the shift control unit 94 sets the secondary target thrust Wouttgt and the primary target thrust Wintgt as the target secondary pressure Pouttgt (= Wouttgt / pressure receiving area) and the target, respectively, based on the pressure receiving areas of the hydraulic actuators 60c and 64c, respectively. It is converted to the primary pressure Pintgt (= Wintgt / pressure receiving area) respectively. The shift control unit 94 sets the target secondary pressure Pouttgt and the target primary pressure Pintgt as the secondary instruction pressure Spout and the primary instruction pressure Spin, respectively.

The shift control unit 94 outputs the primary instruction pressure Spin and the secondary instruction pressure Spout as the hydraulic control command signal Scvt to the hydraulic control circuit 46 so that the target primary pressure Pintgt and the target secondary pressure Pouttgt can be obtained. The hydraulic pressure control circuit 46 regulates the primary pressure Pin and the secondary pressure Pout according to the hydraulic pressure control command signal Scvt.

Here, in the power transmission device 16, the operating state of the second clutch C2 represented by the four states of complete release, complete engagement, release transient, and engagement transient differs depending on the traveling mode and the like. In the belt traveling mode, the second clutch C2 is in a fully engaged state, while in the gear traveling mode, the second clutch C2 is in a completely released state. Further, in the switching control for switching between the gear traveling mode and the belt traveling mode, the second clutch C2 is temporarily in the release transient state or the engagement transient state. Further, when the garage operation in which the shift lever 84 is operated between the N operation position and the D operation position is performed, the second clutch C2 is temporarily put into the release transient state or the engagement transient state. If the operating state of the second clutch C2 is different, the input torque to the continuously variable transmission mechanism 24 is different. That is, the input torque to the continuously variable transmission mechanism 24 is a torque according to the operating state of the second clutch C2.

In addition to the belt traveling mode, it is desirable to realize the target gear ratio γcvttgt of the continuously variable transmission mechanism 24 while preventing the belt slip of the continuously variable transmission mechanism 24 as in the belt traveling mode. Therefore, the shift control unit 94 calculates the input torque to the continuously variable transmission mechanism 24 used for calculating the primary target thrust Wintgt and the secondary target thrust Wouttgt according to the operating state of the second clutch C2. That is, the shift control unit 94 calculates the thrust ratio calculation input torque Tb1 and the belt slip prevention input torque Tb2, respectively, according to the operating state of the second clutch C2. For example, as in the calculation method of the primary target thrust Wintgt and the secondary target thrust Wouttgt described by exemplifying the case where the vehicle 10 is in the belt traveling mode when the second clutch C2 is in the fully engaged state, the thrust ratio. The calculation input torque Tb1 is the turbine torque Tt, and the belt slip prevention input torque Tb2 is the turbine torque Tt in consideration of the minimum guaranteed torque Tblim. When the second clutch C2 is in the release transient state or the engagement transient state, the thrust ratio calculation input torque Tb1 is, for example, a torque value obtained by converting the torque capacity of the second clutch C2 onto the primary shaft 58. .. The torque capacity of the second clutch C2 is calculated based on, for example, the hydraulic control command signal Scbd. Further, when the second clutch C2 is in the completely released state, the thrust ratio calculation input torque Tb1 is set to, for example, zero. Further, even when the second clutch C2 is not in the fully engaged state, the belt slip prevention input torque Tb2 is, for example, a torque in consideration of the minimum guaranteed torque Tblim with respect to the thrust ratio calculation input torque Tb1. ..

As described above, the input torque Tb1 for calculating the thrust ratio and the input torque Tb2 for preventing the belt slip are calculated according to the operating state of the second clutch C2, so that the belt slip can be prevented and the target gear ratio γcvttgt can be followed. It is necessary to accurately determine the operating state of the second clutch C2 in order to achieve both the securing and the securing.

The electronic control device 90 further includes an operating state determining means, that is, an operating state determining unit 96, in order to realize a control function of accurately determining the operating state of the second clutch C2 described above.

The operating state determination unit 96 has four states of complete release, complete engagement, release transient, and engagement transient based on the state of hydraulic pressure control for the second clutch C2 and the state of the difference rotation speed ΔNc2 in the second clutch C2. It is determined whether or not the transition condition of the operating state of the second clutch C2 represented by the state is satisfied. The operating state determination unit 96 determines the operating state of the second clutch C2 based on the determination result of whether or not the transition condition is satisfied. The operation state determination unit 96 acquires the state of hydraulic pressure control for the second clutch C2 based on the hydraulic pressure control command signal Scbd. Further, the operating state determination unit 96 calculates the difference rotation speed ΔNc2 (= Nsec−Nout) in the second clutch C2 based on the secondary rotation speed Nsec and the output shaft rotation speed Nout. In this embodiment, the difference rotation speed ΔNc2 in the second clutch C2 is referred to as C2 difference rotation speed ΔNc2.

The state of the hydraulic pressure control for the second clutch C2 is the tendency of whether the clutch hydraulic pressure of the second clutch C2 is raised or lowered, and / or the state of the indicated pressure in the hydraulic pressure control for the second clutch C2. .. The state of the C2 difference rotation speed ΔNc2 is the actual state of how the second clutch C2 actually operates.

The hydraulic pressure control for the second clutch C2 described above is a hydraulic pressure control for engaging the second clutch C2 or a hydraulic pressure control for releasing the second clutch C2. In this embodiment, the hydraulic pressure control for engaging the second clutch C2 is referred to as C2 engaging hydraulic pressure control, and the hydraulic pressure control for releasing the second clutch C2 is referred to as C2 release hydraulic pressure control. Further, in this embodiment, the hydraulic pressure control command signal Scbd, which is the instruction pressure in the hydraulic pressure control for the second clutch C2, is referred to as C2 instruction hydraulic pressure, and the actual clutch hydraulic pressure supplied from the hydraulic pressure control circuit 46 to the second clutch C2 is C2. It is called actual pressure.

As the C2 engaging hydraulic pressure control, C2 engaging hydraulic pressure control in the control of switching from the state where the first power transmission path PT1 is formed to the state where the second power transmission path PT2 is formed is assumed. The control for switching from the state in which the first power transmission path PT1 is formed to the state in which the second power transmission path PT2 is formed is a clutch-to-clutch shift in which the first clutch C1 is released and the second clutch C2 is engaged. It is an execution control for switching the traveling mode from the gear traveling mode to the belt traveling mode. Alternatively, the C2 engaging hydraulic pressure control is assumed to be the C2 engaging hydraulic pressure control in the control of switching from the neutral state of the power transmission device 16 to the state in which the second power transmission path PT2 is formed. The control for switching from the neutral state of the power transmission device 16 to the state in which the second power transmission path PT2 is formed is the second with the garage operation in which the shift lever 84 is operated from the N operation position to the D operation position in the belt traveling mode. It is a garage engagement control that engages the clutch C2.

As the C2 release hydraulic pressure control, C2 release hydraulic pressure control in the control of switching from the state in which the second power transmission path PT2 is formed to the state in which the first power transmission path PT1 is formed is assumed. The control for switching from the state in which the second power transmission path PT2 is formed to the state in which the first power transmission path PT1 is formed is a clutch-to-clutch shift in which the second clutch C2 is released and the first clutch C1 is engaged. It is a switching control that switches the traveling mode from the belt traveling mode to the gear traveling mode. Alternatively, the C2 release hydraulic pressure control is assumed to be the C2 release hydraulic pressure control in the control for switching from the state in which the second power transmission path PT2 is formed to the neutral state of the power transmission device 16. The control for switching from the state in which the second power transmission path PT2 is formed to the neutral state of the power transmission device 16 is the second operation accompanying the garage operation in which the shift lever 84 is operated from the D operation position to the N operation position in the belt traveling mode. It is a garage release control that releases the clutch C2.

FIG. 10 shows the relationship between the operating state of the second clutch C2 represented by the four states of complete release, complete engagement, release transient, and engagement transient, and the transition condition for determining the switching of the operating state. It is a state transition diagram. FIG. 10 is also a diagram illustrating a main part of the control operation of the electronic control device 90, that is, a control operation for improving the determination accuracy of the operating state of the second clutch C2.

In FIG. 10, when [Condition 1] as a transition condition is satisfied when the second clutch C2 is in the completely released state or the released transient state, the second clutch C2 is switched to the engaged transient state. It is determined that the clutch was clutched. In the engagement process of the second clutch C2 in the C2 engagement hydraulic pressure control, a response delay occurs in the output of the C2 actual pressure with respect to the C2 indicated hydraulic pressure. Therefore, the relationship of "C2 indicated hydraulic pressure> C2 actual pressure" can be guaranteed. On the other hand, when the second clutch C2 is in the engagement transient state, the torque value according to the torque capacity of the second clutch C2 calculated based on the hydraulic control command signal Scbd is the input torque Tb1 for calculating the thrust ratio. Will be done. Therefore, it is possible to secure the belt torque capacity Tcvt even if it is determined that the second clutch C2 has been switched to the engagement transient state only by operating the C2 engagement hydraulic pressure control. ..

Therefore, the above [Condition 1] is that the C2 engaging hydraulic pressure control is operating, that is, the hydraulic pressure control command signal Scbd for the C2 engaging hydraulic pressure control is output. When the operation state determination unit 96 satisfies [Condition 1] that the C2 engagement hydraulic control is operating when the second clutch C2 is in the completely released state or the release transient state, the second clutch C2 is second. It is determined that the clutch C2 has been switched to the engagement transient state.

Further, when [Condition 2] as a transition condition is satisfied when the second clutch C2 is in the fully engaged state, the disengagement transient state, or the engagement transient state, the second clutch C2 is completely disengaged. It is determined that the state has been switched. If the C2 instruction hydraulic pressure in the C2 release hydraulic pressure control is equal to or less than the value that completely releases the second clutch C2 in addition to the C2 release hydraulic pressure control being activated, and the C2 difference rotation speed ΔNc2 is large, the second clutch is released. 2 Even if it is determined that the clutch C2 has been switched to the completely released state, no problem is likely to occur. However, this determination method is effective in a region where the input shaft rotation speed Nin (= primary rotation speed Npri = turbine rotation speed), which is the input rotation speed of the stepless speed change mechanism 24, is high. In a region where the input shaft rotation speed Nin is low, it may be difficult to detect the C2 difference rotation speed ΔNc2. For example, in the switching control from the belt traveling mode to the gear traveling mode in the stopped state of the vehicle 10, the first clutch C1 is engaged after the release of the second clutch C2 and the input shaft rotation speed Nin cannot be increased. The difference rotation speed ΔNc2 cannot be detected. In the region where the input shaft rotation speed Nin is low, it is determined that the second clutch C2 has been switched to the completely released state because the C2 indicated hydraulic pressure in the C2 release hydraulic pressure control has dropped to a value that can guarantee the complete release of the second clutch C2. Will be done. Further, in addition to the above determination method, it may be determined that the second clutch C2 has been switched to the completely released state by determining the neutral state of the power transmission device 16. For example, when the hydraulic control circuit 46 is provided with a known manual valve that is operated in conjunction with the operation of the shift lever 84, the clutch hydraulic pressure supplied to the second clutch C2 with the operation to the N operation position. The original pressure is not supplied, the clutch hydraulic pressure of the second clutch C2 is lowered, and the second clutch C2 is released. When the C2 release hydraulic pressure control is activated by operating the shift lever 84 to the N operation position, for example, the transition condition when the above-mentioned C2 release hydraulic pressure control is operated is used.

Therefore, in the above [Condition 2], in addition to the fact that the C2 release hydraulic pressure control is operating, that is, the hydraulic pressure control command signal Scbd for the C2 release hydraulic pressure control is output, the input shaft rotation speed Nin is predetermined. All of the conditions that the rotation speed Ninf or more, the C2 indicated hydraulic pressure in the C2 release hydraulic pressure control is equal to or less than the first predetermined indicated pressure, and the C2 difference rotation speed ΔNc2 is larger than the first predetermined difference rotation speed ΔNc2f1 are satisfied for a predetermined time TM1 or more. That's what I did. Alternatively, in the above [Condition 2], in addition to the C2 release hydraulic pressure control being activated, the input shaft rotation speed Nin is less than the predetermined rotation speed Ninf, and the C2 indicated hydraulic pressure in the C2 release hydraulic pressure control is the second predetermined indicated pressure. All of the following conditions are satisfied for a predetermined time of TM2 or more. Alternatively, the above [condition 2] is that the neutral state of the power transmission device 16 is confirmed, for example, TM3 or more has elapsed since the shift lever 84 was operated to the N operation position.

The predetermined rotation speed Ninf is, for example, a lower limit rotation speed in a region of a predetermined input shaft rotation speed Nin that can detect a C2 difference rotation speed ΔNc2 for use in determining complete release of the second clutch C2. .. In the above-mentioned first predetermined instruction pressure, second predetermined instruction pressure, first predetermined difference rotation speed ΔNc2f1, predetermined time TM1, predetermined time TM2, and predetermined time TM3, for example, the second clutch C2 is completely released. It is a predetermined threshold value for determining that there is. In particular, the second predetermined instruction pressure is a value lower than the first predetermined instruction pressure, and is an upper limit value of a predetermined C2 instruction hydraulic pressure region that can guarantee that, for example, the second clutch C2 is in a completely released state. Is.

The operating state determination unit 96 is in a region where the input shaft rotation speed Nin is equal to or higher than the predetermined rotation speed Ninf when the second clutch C2 is in a fully engaged state, a release transient state, or an engagement transient state. [Condition 2] that the C2 release hydraulic pressure control is operating, the C2 indicated hydraulic pressure is equal to or less than the first predetermined indicated pressure, and the C2 difference rotation speed ΔNc2 is larger than the first predetermined difference rotation speed ΔNc2f1. In the region where the shaft rotation speed Nin is less than the predetermined rotation speed Ninf, the C2 release hydraulic pressure control is operating, and the C2 indicated hydraulic pressure is equal to or less than the second predetermined indicated pressure [Condition 2], and the power transmission device. When any [Condition 2] of the [Condition 2] that the neutral state of 16 is determined is satisfied, it is determined that the second clutch C2 has been switched to the completely released state.

Further, when [Condition 3] as a transition condition is satisfied when the second clutch C2 is in the state of complete release, the state of release transient, or the state of engagement transient, the second clutch C2 is completely engaged. It is determined that the state has been switched. In addition to the C2 engagement hydraulic pressure control being activated, the C2 indicated hydraulic pressure in the C2 engagement hydraulic pressure control becomes equal to or higher than the value required for engagement of the second clutch C2, and the C2 difference rotation speed ΔNc2 becomes smaller. Then, even if it is determined that the second clutch C2 has been switched to the fully engaged state, no problem is likely to occur. That is, when the change direction of the C2 indicated hydraulic pressure in the hydraulic pressure control with respect to the second clutch C2 is the direction in which the second clutch C2 is engaged, and the actual state of the second clutch C2 can be regarded as a completely engaged state, the first 2 It is determined that the clutch C2 has been switched to the fully engaged state. Further, in addition to the above determination method, when the hydraulic pressure control for the second clutch C2 is shifted from the C2 engaging hydraulic pressure control to the C2 steady hydraulic pressure control which is the hydraulic pressure control for maintaining the second clutch C2 in the fully engaged state. Therefore, it may be determined that the second clutch C2 has been switched to the fully engaged state. For example, when the C2 indicated hydraulic pressure is increased stepwise during the transition from the C2 engaging hydraulic pressure control to the C2 steady hydraulic pressure control, if the determination that the second clutch C2 is in the engaging transient state remains, the determination remains. The input torque Tb1 for calculating the thrust ratio according to the torque capacity of the second clutch C2 based on the increased C2 indicated hydraulic pressure is calculated. Since the input torque Tb1 for calculating the thrust ratio calculated in this way may not be appropriate, it may be determined that the second clutch C2 has been switched to the fully engaged state at the time of transition to the C2 steady hydraulic control. ..

Therefore, in the above [Condition 3], in addition to the C2 engaging hydraulic pressure control being activated, the C2 indicated hydraulic pressure in the C2 engaging hydraulic pressure control is equal to or higher than the third predetermined indicated pressure, and the C2 difference rotation speed ΔNc2 is the second. All of the conditions that the rotation speed is smaller than the predetermined difference rotation speed ΔNc2f2 are satisfied for the predetermined time TM4 or more. Alternatively, the above [Condition 3] is that the hydraulic pressure control for the second clutch C2 is shifted from the C2 engaging hydraulic pressure control to the C2 steady hydraulic pressure control. The third predetermined indicated pressure, the second predetermined difference rotation speed ΔNc2f2, and the predetermined time TM4 are predetermined threshold values for determining, for example, that the second clutch C2 is in a fully engaged state.

In the operation state determination unit 96, when the second clutch C2 is in the completely released state, the release transient state, or the engaging transient state, the C2 engaging hydraulic pressure control is activated and the C2 indicating hydraulic pressure is the second. [Condition 3] that the C2 difference rotation speed ΔNc2 is smaller than the second predetermined difference rotation speed ΔNc2f2, and the hydraulic pressure control for the second clutch C2 is changed from the C2 engagement hydraulic pressure control to the C2 steady hydraulic pressure. When any [Condition 3] of the [Condition 3] that the control is shifted to is satisfied, it is determined that the second clutch C2 has been switched to the fully engaged state.

Further, if [Condition 4] as the transition condition is satisfied while the second clutch C2 is in the fully engaged state, it is determined that the second clutch C2 has been switched to the release transient state. If it is determined that the second clutch C2 has been switched to the release transient state, if the C2 difference rotation speed ΔNc2 is increased in addition to the C2 release hydraulic pressure control being activated, no problem is likely to occur. Even if the C2 release hydraulic pressure control is activated, the actual condition of the second clutch C2 is in a completely engaged state, for example, when the solenoid valve that regulates the clutch hydraulic pressure supplied to the second clutch C2 fails. The input torque Tb2 for preventing belt slip, which is smaller than the torque actually input to the continuously variable transmission mechanism 24, is calculated, and there is a concern that belt slip may occur. In order to avoid such belt slippage, it is not determined that the second clutch C2 has been switched to the release transient state only by operating the C2 release hydraulic control, and the C2 difference rotation speed ΔNc2 is increased. Consider that the increase is a transition condition.

Therefore, the above [condition 4] is that the condition that the C2 difference rotation speed ΔNc2 is the third predetermined difference rotation speed ΔNc2f3 or more is satisfied for a predetermined time TM5 or more in addition to the C2 release hydraulic pressure control being operated. The third predetermined difference rotation speed ΔNc2f3 and the predetermined time TM5 are predetermined threshold values for determining, for example, that the second clutch C2 is in the release transient state, respectively.

In the operating state determination unit 96, when the second clutch C2 is in a fully engaged state, the C2 release hydraulic control is operating, and the C2 difference rotation speed ΔNc2 is equal to or higher than the third predetermined difference rotation speed ΔNc2f3. When [Condition 4] is satisfied, it is determined that the second clutch C2 has been switched to the release transient state.

Further, if [Condition 5] as the transition condition is satisfied while the second clutch C2 is in the engagement transient state, it is determined that the second clutch C2 has been switched to the release transient state. When it is determined that the second clutch C2 has been switched to the release transient state when the C2 engagement hydraulic control is shifted to the C2 release hydraulic control, no problem is likely to occur. When the second clutch C2 is in the engagement transient state, the C2 difference rotation speed ΔNc2 is generated to some extent, and the input torque Tb1 for calculating the thrust ratio is the second clutch calculated based on the hydraulic control command signal Scbd. The torque value is set according to the torque capacity of C2. Therefore, it is determined that the second clutch C2 has been switched to the release transient state only by operating the C2 release hydraulic pressure control.

Therefore, the above [Condition 5] is that the C2 release hydraulic control is operating. When the operating state determination unit 96 satisfies [Condition 5] that the C2 release hydraulic control is operating when the second clutch C2 is in the engagement transient state, the second clutch C2 is released transiently. It is determined that the state has been switched to.

The shift control unit 94 calculates the input torque to the continuously variable transmission mechanism 24 used for calculating the primary target thrust Wintgt and the secondary target thrust Wouttgt according to the operating state of the second clutch C2 determined by the operating state determining unit 96. do.

FIG. 11 is a flowchart illustrating a control operation for improving the determination accuracy of the operation state of the second clutch C2, that is, the main part of the control operation of the electronic control device 90, and is, for example, repeatedly executed.

In FIG. 11, first, in step S10 corresponding to the function of the operation state determination unit 96 (hereinafter, step is omitted), the state of hydraulic pressure control for the second clutch C2 is acquired. Further, the C2 difference rotation speed ΔNc2 is calculated. Next, in S20 corresponding to the function of the operation state determination unit 96, the operation state of the second clutch C2 is determined. That is, which of the four states represented by the complete release, the complete engagement, the release transient, and the engagement transient is the operating state of the second clutch C2 is determined by the control operation in FIG. 10 described above. .. Next, in S30 corresponding to the function of the operation state determination unit 96, it is determined whether or not the operation state of the second clutch C2 is in the completely released state. If this determination in S30 is denied, it is determined in S40 corresponding to the function of the operating state determination unit 96 whether or not the operating state of the second clutch C2 is in a completely engaged state. If this determination in S40 is denied, it is determined in S50 corresponding to the function of the operating state determination unit 96 whether or not the operating state of the second clutch C2 is the engagement transient state. If the determination in S30 is affirmed, the thrust ratio calculation input torque Tb1 corresponding to the completely released state of the second clutch C2 is calculated in S60 corresponding to the function of the shift control unit 94. Next, in S70 corresponding to the function of the shift control unit 94, the belt slip prevention input torque Tb2 corresponding to the completely released state of the second clutch C2 is calculated. If the determination in S40 is affirmed, the thrust ratio calculation input torque Tb1 corresponding to the fully engaged state of the second clutch C2 is calculated in S80 corresponding to the function of the shift control unit 94. Next, in S90 corresponding to the function of the shift control unit 94, the belt slip prevention input torque Tb2 corresponding to the state of complete engagement of the second clutch C2 is calculated. If the determination in S50 is affirmed, the thrust ratio calculation input torque Tb1 corresponding to the engagement transient state of the second clutch C2 is calculated in S100 corresponding to the function of the shift control unit 94. Next, in S110 corresponding to the function of the shift control unit 94, the belt slip prevention input torque Tb2 corresponding to the engagement transient state of the second clutch C2 is calculated. If the determination of S50 is denied, the thrust ratio calculation input torque Tb1 corresponding to the release transient state of the second clutch C2 is calculated in S120 corresponding to the function of the shift control unit 94. Next, in S130 corresponding to the function of the shift control unit 94, the belt slip prevention input torque Tb2 corresponding to the release transient state of the second clutch C2 is calculated. Following the above S70, following the above S90, following the above S110, or following the above S130, in the S140 corresponding to the function of the shift control unit 94, the primary target thrust Wintgt by the control operation in FIG. 5 described above. And the secondary target thrust Wouttgt is calculated.

As described above, according to the present embodiment, four of complete release, complete engagement, release transient, and engagement transient are based on the state of hydraulic pressure control for the second clutch C2 and the state of C2 difference rotation speed ΔNc2. It is determined whether or not the transition condition of the operating state of the second clutch C2 represented by the two states is satisfied, and the operating state of the second clutch C2 is determined based on the determination result of whether or not the transition condition is satisfied. Therefore, the tendency of whether the clutch hydraulic pressure of the second clutch C2 is raised or lowered, and / or the state of the C2 indicated hydraulic pressure, is added to the actual state of the second clutch C2, and the second clutch is used. The four states of the clutch C2 can be appropriately determined. Therefore, the accuracy of determining the operating state of the second clutch C2 can be improved.

Further, according to the present embodiment, the input torque to the continuously variable transmission mechanism 24 used for calculating the primary target thrust Wintgt and the secondary target thrust Wouttgt is calculated according to the determined operating state of the second clutch C2. Therefore, the continuously variable transmission mechanism 24 can be appropriately controlled by using the input torque that matches the operating state of the second clutch C2 that has been accurately determined.

Further, according to the present embodiment, the input torque to the continuously variable transmission mechanism 24 is the input torque Tb1 for calculating the thrust ratio and the input torque Tb2 for preventing belt slippage, so that the continuously variable transmission mechanism 24 should be appropriately controlled. Can be done.

Further, according to the present embodiment, when the above [Condition 1] is satisfied when the second clutch C2 is in the completely released state or the released transient state, the second clutch C2 is engaged transiently. Since it is determined that the state has been switched to the above state, the engagement transient state of the second clutch C2 can be appropriately determined.

Further, according to the present embodiment, when the second clutch C2 is in the fully engaged state, the disengaged transient state, or the engaged transient state, and the above [Condition 2] is satisfied, the second clutch C2 is satisfied. Since it is determined that the clutch C2 has been switched to the completely released state, the completely released state of the second clutch C2 can be appropriately determined.

Further, according to the present embodiment, when the second clutch C2 is in the completely released state, the released transient state, or the engaged transient state, and the above [Condition 3] is satisfied, the second clutch is satisfied. Since it is determined that C2 has been switched to the fully engaged state, the fully engaged state of the second clutch C2 can be appropriately determined.

Further, according to the present embodiment, when the above [condition 4] is satisfied when the second clutch C2 is in the fully engaged state, the second clutch C2 is switched to the release transient state. Since it is determined that the clutch C2 has been released, the state of the release transient of the second clutch C2 can be appropriately determined.

Further, according to the present embodiment, when the above [Condition 5] is satisfied when the second clutch C2 is in the engagement transient state, the second clutch C2 is switched to the release transient state. Since it is determined that the clutch C2 has been released, the state of the release transient of the second clutch C2 can be appropriately determined.

Further, according to this embodiment, it is possible to improve the accuracy of determining the operating state of the second clutch C2 in the C2 engaging hydraulic pressure control or the C2 release hydraulic pressure control.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is also applicable to other aspects.

For example, in the flowchart of FIG. 11 in the above-described embodiment, the flowchart of FIG. 11 may be changed as appropriate, such that each step of S20-S50 may be executed in one step.

Further, in the above-described embodiment, the continuously variable transmission mechanism 24 is a belt-type continuously variable transmission, but the present invention is not limited to this mode. For example, the continuously variable transmission mechanism provided in the second power transmission path PT2 may be a known toroidal type continuously variable transmission.

Further, in the above-described embodiment, the second clutch C2 is provided in the power transmission path between the secondary pulley 64 and the output shaft 30, but the present invention is not limited to this mode. For example, the secondary shaft 62 may be integrally connected to the output shaft 30, and the primary shaft 58 may be connected to the input shaft 22 via the second clutch C2. That is, the second clutch C2 may be provided in the power transmission path between the primary pulley 60 and the input shaft 22.

Further, in the above-described embodiment, the gear mechanism 28 is a gear mechanism in which one gear stage having a gear ratio on the lower side than the lowest gear ratio γmax of the continuously variable transmission mechanism 24 is formed. It is not limited to the embodiment. For example, the gear mechanism 28 may be a gear mechanism in which a plurality of gear stages having different gear ratios are formed. That is, the gear mechanism 28 may be a stepped transmission that shifts to two or more speeds. Alternatively, the gear mechanism 28 is a gear mechanism that forms a gear ratio on the higher side than the highest gear ratio γmin of the continuously variable transmission mechanism 24 and / or a gear ratio on the lower side than the lowest gear ratio γmax. There may be.

Further, in the above-described embodiment, the traveling mode of the power transmission device 16 is switched by using a predetermined upshift line and downshift line, but the present invention is not limited to this mode. For example, the traveling mode of the power transmission device 16 may be switched by calculating the target driving force Fwtgt based on the vehicle speed V and the accelerator operation amount θacc and setting a gear ratio that can satisfy the target driving force Fwtgt. ..

Further, in the above-described embodiment, the torque converter 20 is used as the fluid type transmission device, but the present invention is not limited to this embodiment. For example, instead of the torque converter 20, another fluid type transmission device such as a fluid coupling having no torque amplification action may be used. Alternatively, this fluid transmission device does not necessarily have to be provided. Further, although the meshing clutch D1 is provided in the first power transmission path PT1 via the gear mechanism 28, the meshing clutch D1 does not necessarily have to be provided in carrying out the present invention.

It should be noted that the above is only one embodiment, and the present invention can be carried out in a mode in which various changes and improvements are made based on the knowledge of those skilled in the art.

12: Engine (power source)
14: Drive wheel 16: Vehicle power transmission device 22: Input shaft (input rotating member)
24: Continuously variable transmission mechanism (belt type continuously variable transmission)
28: Gear mechanism 30: Output shaft (output rotating member)
60: Primary pulley 60c: Hydraulic actuator 64: Secondary pulley 64c: Hydraulic actuator 66: Transmission belt (transmission element)
90: Electronic control device (control device)
94: Shift control unit 96: Operation state determination unit C1: First clutch (first engagement device)
C2: 2nd clutch (2nd engaging device)
PT1: 1st power transmission path PT2: 2nd power transmission path

Claims (9)

To transmit the power from the input rotating member to the output rotating member, which is provided in parallel between the input rotating member to which the power of the power source is transmitted and the output rotating member that outputs the power to the drive wheel. The plurality of power transmission paths include a first power transmission path via a gear mechanism having a gear stage formed by engagement of the first engagement device, and a second power transmission path. A control device for a vehicle power transmission device having a second power transmission path via a stepless speed change mechanism formed by engagement of the engagement device.
Based on the state of hydraulic control for the second engaging device and the state of the differential rotation speed in the second engaging device, it is represented by four states of complete release, complete engagement, release transient, and engagement transient. It is determined whether or not the transition condition for determining the switching of the operating state of the second engaging device is satisfied, and the operation of the second engaging device is performed based on the determination result of whether or not the transition condition is satisfied. A control device for a power transmission device for a vehicle, comprising: an operating state determination unit for determining which of the four states the state has been switched to . The continuously variable transmission mechanism is a belt-type continuously variable transmission having a primary pulley, a secondary pulley, and a transmission element wound between the pulleys.
The target value of the thrust of the primary pulley that clamps the transmission element applied by the hydraulic actuator of the primary pulley, and the target value of the thrust of the secondary pulley that clamps the transmission element applied by the hydraulic actuator of the secondary pulley. The first aspect of claim 1, further comprising a shift control unit that calculates the input torque to the continuously variable transmission mechanism used for the calculation according to the determined operating state of the second engaging device. Control device for vehicle power transmission device. The input torque to the stepless speed change mechanism is the first used for calculating the thrust ratio, which is the value of the ratio between the thrust of the primary pulley and the thrust of the secondary pulley, which realizes the target speed change ratio of the stepless speed change mechanism. The second aspect of claim 2, wherein the input torque is a second input torque used for calculating the thrusts of the primary pulley and the secondary pulley, which are necessary for preventing the transmission element from slipping. Control device for vehicle power transmission. The operating state determination unit satisfies the transition condition that the hydraulic control for engaging the second engaging device is operating when the second engaging device is in a completely released state or a release transient state. The control device for the vehicle power transmission device according to any one of claims 1 to 3, wherein it is determined that the second engagement device has been switched to the engagement transient state. In the operating state determination unit, when the second engaging device is in a fully engaged state, a release transient state, or an engagement transient state, the input rotation speed of the stepless speed change mechanism is equal to or higher than a predetermined rotation speed. In the region, the hydraulic control for releasing the second engaging device is operating, and the instruction pressure in the hydraulic control for the second engagement device is equal to or less than the first predetermined instruction pressure, and the first In the transition condition that the difference rotation speed in the two engagement devices is larger than the first predetermined difference rotation speed, and in the region where the input rotation speed of the stepless speed change mechanism is less than the predetermined rotation speed, the second engagement device is used. The transition condition that the hydraulic pressure control to be released is operating and the instruction pressure in the hydraulic pressure control for the second engaging device is equal to or less than the second predetermined instruction pressure lower than the first predetermined instruction pressure, and the first. If any of the transition conditions that the neutral state of the vehicle power transmission device in which both the engaging device and the second engaging device are released is determined, the first transition condition is satisfied. 2. The control device for a vehicle power transmission device according to any one of claims 1 to 4, wherein it is determined that the engaging device has been switched to the completely released state. In the operating state determination unit, when the second engaging device is in a completely released state, a release transient state, or an engaging transient state, the hydraulic control for engaging the second engaging device is activated. The transition that the instruction pressure in the hydraulic control for the second engaging device is equal to or higher than the third predetermined instruction pressure, and the difference rotation speed in the second engagement device is smaller than the second predetermined difference rotation speed. It is said that the conditions and the hydraulic control for the second engaging device have been shifted from the hydraulic control for engaging the second engaging device to the hydraulic control for maintaining the second engaging device in a fully engaged state. Any one of claims 1 to 5, wherein when any of the transition conditions is satisfied, it is determined that the second engaging device has been switched to the fully engaged state. The control device for the vehicle power transmission device according to the above. In the operating state determination unit, when the second engaging device is in a fully engaged state, the hydraulic control for releasing the second engaging device is operating, and the second engaging device is in the second engaging device. Claims 1 to 6 are characterized in that when the transition condition that the difference rotation speed is equal to or higher than the third predetermined difference rotation speed is satisfied, it is determined that the second engaging device has been switched to the release transient state. The control device for the vehicle power transmission device according to any one of the above items. When the transition condition that the hydraulic control for releasing the second engaging device is operating is satisfied when the second engaging device is in the engagement transient state, the operating state determination unit is in the engagement transient state. The control device for a vehicle power transmission device according to any one of claims 1 to 7, wherein it is determined that the second engaging device has been switched to the release transient state. The hydraulic control for the second engaging device is a hydraulic control for engaging the second engaging device or a hydraulic control for releasing the second engaging device.
The hydraulic control that engages the second engaging device engages the second engaging device in the control of switching from the state in which the first power transmission path is formed to the state in which the second power transmission path is formed. In hydraulic control, or in control of switching from the neutral state of the vehicle power transmission device in which both the first engagement device and the second engagement device are released to the state in which the second power transmission path is formed. It is a hydraulic control that engages the second engaging device.
The hydraulic pressure control for releasing the second engaging device is the hydraulic pressure for releasing the second engaging device in the control for switching from the state in which the second power transmission path is formed to the state in which the first power transmission path is formed. The first aspect is the hydraulic control for releasing the second engaging device in the control or the control for switching from the state in which the second power transmission path is formed to the neutral state of the vehicle power transmission device. A control device for a vehicle power transmission device according to any one of items 1 to 8.

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